Adytum was founded by the inhabitants of the demonstration Vault. The community was fairly self-sufficient, growing its own food and manufacturing ammunition from chemical components garnered on location, (from brahmin dung for example), to exchange for necessary supplies. Aside from the inhabitants eking out an existence, the Adytum is home to several scavengers under the informal leadership of Sammael, who comb the city for long lost artifacts and information.
The town was well fortified, surrounded by a double chain-link fence and patrolled by armed Regulators. It became dependent on deliveries from the Hub when their hydroponic farms broke down, with the merchants abusing their position as the sole sustenance of the community, making a tidy profit on ammunition from Adytum.
It is not known what is the canon outcome of the Vault Dweller's adventures in the Boneyard. The only available piece of information comes from the Vault Dweller's memoirs: I found many enemies, and a few friends, in the Boneyard. I killed when necessary and learned more about the nature of my true foes. It is not known for certain, however, whether the Vault Dweller did uncover the assassination of Zimmerman's son by the Regulators and their attempt at putting the blame on the Blades, and whether Adytum was freed from Regulator rule. We don't even know if he or she killed the deathclaws, so it is entirely possible that Adytum joined the NCR under the control of the Regulators, after the Vault Dweller was fooled into killing the Blades.